This invention relates to vehicle seat assemblies, and more particularly, to a forming tool including a removable style line insert for use in producing vehicle seat trim covers.
Typically, in the production of vehicle seat trim covers, forming tools are constructed and used which have a surface contour which is complementary to the final desired shape of the vehicle seat or back. One exile of such forming tools is disclosed in U.S. Pat. No. 4,860,415, entitled "Vehicle Seat Assembly With Pour In Place For Body," which was issued Aug. 29, 1989, In the process disclosed in this patent, material for a vehicle seat cover is placed inside out on a forming tool which has the desired complementary contours to the finished product. The material is shaped to the contours of the forming tool by vacuum forming. Another known method for producing vehicle seat assemblies uses complementary shaped forming tools. The seat cover material is shaped by pressing the material between the complementary shaped forming tools under conditions of heat and pressure. In both methods, the forming tools must be individually made with the desired surface contours. Consequently, any small change in the styling detail requires a completely new forming tool or set of forming tools that incorporates the final shape for the vehicle seat being produced. Moreover, changing a forming tool or forming tool set is a relatively difficult procedure because the forming tools are large and bulky and are relatively heavy. Also, when the cover fabric is shaped by pressing it between complementary forming tools, the forming tools are heated to a temperature of about 230 degrees Fahrenheit. Consequently, special procedures are required for handling the forming tools during a changeover. In addition, when complementary forming tools are used, a tooling changeover requires that both of the forming tools be replaced and so the forming tools must be realigned with one another during the retooling operation.
Forming tools having removable inserts which permit modification of the insert instead of replacement of the entire forming tool are described in U.S. Pat. No. 4,975,135 issued on Dec. 4, 1990. The forming tools described in this patent allow interchange of styles for producing vehicle seat covers having differing contours as consumer demand dictates. However, the insert is used in shaping substantially the entire "A" surface of the vehicle seat, that is about 80% of the "A" surface. Because the insert in itself defines nearly all of the forming surface for the forming tool, the insert, albeit a generally flat plate, is nearly as large as the forming tool with which it is assembled. In one method disclosed in this patent, vacuum forming is used to draw the cover fabric onto the forming tool to shape the cover fabric to the desired shape. However, this requires vacuum connections to the forming tool which limits automation of this process for shaping seat cover fabric. In another process disclosed in this patent, complementary forming tools are used and the cover fabric is pressed between the two complementary forming tools under conditions of heat and pressure. In this process, both forming tools require a style insert and both inserts must be changed whenever a style line change is called for.